Relay actuating circuit



June 9, 1964 T. R. SMITH 3,136,926

RELAY ACTUATING CIRCUIT Filed Jan. 3l, 1961 AGENT 3,136,926y RELAY ACTUATIN G CIRCUIT Thomas R. Smith, Newton, Iowa, assignor'to The Maytag Company, Newton, Iowa, a corporation of Delaware Filed Jan. 31, 1961, SertNo. 86,107

` 2 Claims. (Cl. 317-130) This invention relates to a circuit for actuating a relay, and, more particularly, to a condenser-,resistance circuit which causes a relay to operate after the condenser becomes charged .to a predetermined voltage.

This is acontinuation-inepart of my copendingapplica-yl tion, Serial No. 22,323 tiled April 14, 1960 now abandoned. f

It is an object of the present invention to provide La circuit which contains sufficiently high resistance in series with a manually operated switch so as to insure safety to the operator, for example, in a circuit connected to the conventional 110 volt, 60 cycle line. Itis another object of the invention to provide a circuit yfor operation of a relay after a ktime delay. It is a still further object of the invention to provide a circuit for actuation of a relay after a time delay. It is a still further object of the in- Y vention to provide a circuit for actuation of a relay which is independent of the relay circuit.' Further objects 'and y advantages of this invention will `become evident as the description proceeds and from an examination of the accompanying drawing which illustrates one embodiment of the invention and in which similar numerals refer to similar parts throughout lthe several views.

In the drawing: FIGURE l is a diagram present invention; p

FIGURE 2 is a modication ofthe circuit shown in FIGURE l permitting the use of a single source of potential. y n v y i* Referring toFIGURE l, a switch 10 controls the source of power supplied by line L1, L2, for example, 110 volts, 60 cycle alternating current. A selenium half-wave rectifier 11 is in series with the switch 10. Connected in series with the power source and rectifier 11 are caof acircuit embodying the pacitor 2l) and series resistors 14 and k15. The capacitoris gradually charged by the D.C. circuit from the rectiiier 11 through resistors 14 and 15 in accordance with wellknown condenser-resistor principles. The resistors also provide a safety factor in reducing the Voltage drop at other points in the circuit.

It is clear that a direct current power source may be employed rather than alternating current. It so, the rectifier 11 may be eliminated. y

A gaseous discharge tube, such as a neon lamp 22 is in parallel to capacitor 20. Neon lamp 22 normally has a high resistance, however, when the charge on the capacitor reaches a predetermined Value, the gas is ionized and the circuitis conducted therethrough to produce visible discharge.

y A light responsive resistor in the form of a light sensitive cell 30 ispositioned to be illuminated by the neon lamp 22k. One side of the light sensitive cell isk connected by line 31 to a source of power, and the other side of the light sensitive cell is connected to relay 34 through line 36. The other side of the relay is connected to power line 38. Normally, when dark, Vthe light sensitive cell 30 has a very high resistance. However, when illumined,

. of limitation.

parts, as well as the substitution of equivalents are con# 2" the resistance of the cell 30 is greatly reduced and completes the circuit to energize relay 34.

Relay 34 operates switch contact 40. Switch contact ,40y closes the circuit indicated by lines-41 and 42.

By way of'exam'pl'e, if the power between lines L1 and L2 is ll0`volts, 60 cycle alternating current, the capacitor 20 may bea siX` microfarad paper condenser, and the total resistance of resistors 14 and 15 may be 3l megohms, with resistor 14 of 30 megohrns and resistor 15 of l megohm. The neon lamp 22 in this arrangement may be designed to tire at 68 to 76 volts'.

Referring now to FIGURE 2, the circuit is identical to the one shown in FIGURE 1 except that the powerv` source for the relay circuit is theysame as the power source employed for the condenser 20 and neon tube 22. It will be noted that lines 31, 32 which have in series therewith the light sensitive cell 30 and relay 34 are connected to power lines L1 and L2. f

In the drawing and specification there has been sety forth a preferred embodiment of theinvention, and although specitic terms are employed, these are used in a generic and descriptive sense only, and not for purposes Changes in form and theproportion of templated, ascircumstances may suggest or render expedient, without departing from the spirit or scope of this invention as further defined in the following claims. ,n

I claim: l. In a`relay actuating circuitry, an electric relay to be actuated, a iirstpower source for supplying alternating current, a irst circuit having a rectifier for converting alternating to direct current,"switch means for completing said first circuit to said first power source, said irst circuit including capacitance and resistance connected in series for charging said capacitance through said resistance when said power source is connected by said switch means, a normally de-energized radiation generating element connected in parallel to said capacitance operable` to generate radiation when said capacitance is charged to a predetermined voltage, a second power source, second circuit means connected to said second power source for energizing said electric relay, said second circuitelectrically isolated fromksaid iirst circuit, and ak radiation responsive resistor having high resistance in the dark and low resistance when radiated by said radiation generating element, said radiation responsive resistor positioned for illumination by said radiation generating element, said electric relay and radiation responsive resistor connected in series in said second circuit means to said second power source. n

2.` A time delay circuit for actuating a relay comprising, a charging capacitance and a charging resistance connected in series in a normally de-energized rst circuit, av first power source, switch means for connecting said charging capacitance and said charging resistance to said first power source tok energize said rst circuit and charge said capacitor over a timel delayperiod, a normally deenergized radiation generating element connected in parallel to said capacitance operable to generate radiation after the charge on said capacitance has achieved a predetermined voltage, a second power source, an electric relay having a current coil for actuation by said second power source, second circuit meansconnected to said second power source for energizing said electric relay, said second circuit electrically isolatedfrom said first circuit,

3,136,926 Patented June 1964 and a radiation responsive resistor having high resistance generating element whereupon said radiation responsive in the dark Land. low resistance whenradiated by said v.resistor..is radiated to energize and operate said relay radiation generating element, said radiation responsive means.

resistor positioned for illumination by said radiation generating element, said electric relay coil and radiation re- 5 References Cited in the me of this Patent sponsive resistor connected in series in said second circuit UNITED STATES PATENTS means to said second power source, whereby the closing 2,057,472 Bonds Oct, 13, 1936 of said switch means causes said capacitance to charge 2,621,808 Blakeney Dec. 16, 1952 and the voltage thereacross to increase during a time 10 2,838,719 Chitty June 10,1958 3,040,178 Lyman et a1. 'June 19, 1962 delay until it equals the ring voltage of said radiation 

1. IN A RELAY ACTUATING CIRCUITRY, AN ELECTRIC RELAY TO BE ACTUATED, A FIRST POWER SOURCE FOR SUPPLYING ALTERNATING CURRENT, A FIRST CIRCUIT HAVING A RECTIFIER FOR CONVERTING ALTERNATING TO DIRECT CURRENT, SWITCH MEANS FOR COMPLETING SAID FIRST CIRCUIT TO SAID FIRST POWER SOURCE, SAID FIRST CIRCUIT INCLUDING CAPACITANCE AND RESISTANCE CONNECTED IN SERIES FOR CHARGING SAID CAPACITANCE THROUGH SAID RESISTANCE WHEN SAID POWER SOURCE IS CONNECTED BY SAID SWITCH MEANS, A NORMALLY DE-ENERGIZED RADIATION GENERATING ELEMENT CONNECTED IN PARALLEL TO SAID CAPACITANCE OPERABLE TO GENERATE RADIATION WHEN SAID CAPACITANCE IS CHARGED TO A PREDETERMINED VOLTAGE, A SECOND POWER SOURCE, SECOND CIRCUIT MEANS CONNECTED TO SAID SECOND POWER SOURCE FOR ENERGIZING SAID ELECTRIC RELAY, SAID SECOND CIRCUIT ELECTRICALLY ISOLATED FROM SAID FIRST CIRCUIT, AND A RADIATION RESPONSIVE RESISTOR HAVING HIGH RESISTANCE IN THE DARK AND LOW RESISTANCE WHEN RADIATED BY SAID RADIATION GENERAING ELEMENT, SAID RADIATION RESPONSIVE RESISTOR POSITIONED FOR ILLUMINATION BY SAID RADIATION GENERATING ELEMENT, SAID ELECTRIC RELAY AND RADIATION RESPONSIVE RESISTOR CONNECTED IN SERIES IN SAID SECOND CIRCUIT MEANS TO SAID SECOND POWER SOURCE. 